Format

Send to

Choose Destination
Biochem Biophys Res Commun. 1992 Oct 30;188(2):773-9.

Selective inhibition of protein tyrosine phosphatase activities by H2O2 and vanadate in vitro.

Author information

1
Department of Chemical Immunology, Weizmann Institute of Science, Rehovot, Israel.

Abstract

Acute (10-30 min) treatment of intact rat hepatoma (Fao) cells with H2O2, inhibits in vivo protein tyrosine phosphatase activity. Vanadate markedly potentiates this effect although it has only trivial effects of its own. Here we show that H2O2 inhibits a protein tyrosine phosphatase activity, but not a p-nitro phenyl phosphate hydrolysing activity, in cytosolic extracts of these cells. This effect is completely reversed by 10 mM dithiothreitol. Other oxidants have similar inhibitory effects. Vanadate inhibits the protein tyrosine phosphatase activity in vitro, and its effects are additive with those of H2O2. These findings suggest that H2O2 and vanadate interact with the protein tyrosine phosphatases at two independent sites. They also suggest that in intact cells H2O2 has a direct inhibitory effect on protein tyrosine phosphatase activity and an indirect effect of facilitating the entry of vanadate.

PMID:
1445322
DOI:
10.1016/0006-291x(92)91123-8
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center